Police are investigating an anti-U.S. rant posted by Abdul Razak Ali Artan on Facebook just minutes before his attack on Ohio State University students on Monday, according to ABC News.

“I can’t take it anymore. America! Stop interfering with other countries, especially the Muslim Ummah,” the post reads according to NBC News. “We are not weak. We are not weak, remember that.”

The post was published minutes before the beginning of Artan’s rampage, which left 11 people injured. Authorities are investigating his Facebook page to see if the incident was a terrorism attack, according to CNN.

“If you want us Muslims to stop carrying lone wolf attacks, then make peace,” the post reads. “We will not let you sleep unless you give peace to the Muslims.”

A law enforcement official told NBC News investigators they were also trying to determine whether Artan had problems in his personal life or if there was something that had pushed him over the edge.

Artan, 20, was a Somali refugee who was in the U.S. as a legal permanent resident. Authorities have not yet determined a motive for the attack and the investigation is ongoing.

Artan left his birth country with his family in 2007, lived in Pakistan for a time and then came to the U.S. in 2014.

The incident began Monday morning when the suspect drove a vehicle into several people on campus before leaving the car and slashing victims with a knife.

About 11 people were hospitalized, according to CNN, with one in critical condition. Artan was killed by OSU Police Officer Alan Horujko, 28, who shot him less than one minute after the attack began.